1. Field of the Invention
This invention relates to a process for making substantially homogeneous terpolymers of vinyl pyrrolidone, a quaternary amino monomer and a hydrophobic monomer, for use in hair care applications.
2. Description of the Prior Art
Several synthetic polymers containing vinyl lactams are presently being used in cosmetic formulations, particularly in hair care products, to contribute body, set retention and conditioning to such products.
Representative of the art in this field are the following U.S. Pat. Nos. 3,914,403; 3,954,960; 4,057,533; 4,210,161; 4,586,518; 4,753,793; 4,764,363; 4,834,968; 4,842,850; 4,902,499; 4,906,459; 4,923,694; 4,963,348; 4,983,377; 5,011,895 and 5,015,708; and WO 91/15186; WO 91/15185; EPO 0412704A2; EPO 0412707A1; and JP 57126409.
These synthetic polymers generally are made by a "one-pot" polymerization process in which selected amounts of the several monomers are reacted together. The composition of the thus-formed polymer is considered as being the same as the composition of the charged monomers. However, such conventional non-homogeneous polymerization processes can provide only a mixture of polymers of various compositions, and, additionally, an indeterminate amount of homopolymers and undesired copolymers.
Accordingly, it is an object of this invention to provide a homogeneous polymerization process for making substantially homogeneous copolymers of vinyl pyrrolidone, a quaternary amino monomer and a hydrophobic monomer.
Another object of this invention is to provide a clear, aqueous solution of substantially homogeneous terpolymers of vinyl pyrrolidone (VP), 3-methacrylamidopropyl trimethylammonium chloride (MAPTAC), and RMA where R is C.sub.4 -C.sub.32, and MA is methacrylate, preferably octadecyl methacrylate (ODMA), in a compositional range, by weight, of 55-99% VP, 0.5-49% MAPTAC and 0.5-49% ODMA.
Still another object herein is to provide clear, aqueous solutions of substantially homogeneous terpolymers of VP, MAPTAC and RMA in a predetermined compositional range and at a selected solids level, which, upon formulation into hair styling and conditioning compositions, will provide enhanced water solubility, and improved fixative, conditioning, and hair holding properties for the user.